Vehicular camera focus test system using light collimator in controlled test chamber

ABSTRACT

A method for testing a vehicular camera includes providing a vehicular camera and an environmentally-controlled chamber that has a window allowing visible light to pass into the interior of the chamber. A light-collimating device is provided exterior the environmentally-controlled chamber, and the vehicular camera is disposed within the interior of the environmentally-controlled chamber. Light emitted by the device passes through a window of the chamber to project a target within the chamber. Image data is captured with the vehicular camera that includes at least a portion of the projected target. Responsive to processing by an image processor of image data captured by the vehicular camera, a characteristic of the vehicular camera is estimated.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the filing benefits of U.S. provisionalapplication Ser. No. 63/362,061, filed Mar. 29, 2022, which is herebyincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to a vehicular vision system fora vehicle and, more particularly, to a testing system for a vehicularvision system that utilizes one or more cameras.

BACKGROUND OF THE INVENTION

Use of imaging sensors in vehicle imaging systems is common and known.Examples of such known systems are described in U.S. Pat. Nos.5,949,331; 5,670,935 and/or 5,550,677, which are hereby incorporatedherein by reference in their entireties.

SUMMARY OF THE INVENTION

A method for testing a vehicular camera includes providing a vehicularcamera and providing an environmentally-controlled chamber. Theenvironmentally-controlled chamber includes a window allowing visiblelight to pass from the exterior of the environmentally-controlledchamber into the interior of the environmentally-controlled chamber. Themethod includes positioning a light-collimating device exterior theenvironmentally-controlled chamber. With the light-collimating deviceoperating to emit collimated light, collimated light emitted by thelight-collimating device passes through the window of theenvironmentally-controlled chamber to project a target within theenvironmentally-controlled chamber. The method also includes disposingthe vehicular camera within the interior of theenvironmentally-controlled chamber. With the light-collimating deviceoperating to emit collimated light that passes through the window of theenvironmentally-controlled chamber to project the target within theenvironmentally-controlled chamber, the vehicular camera views at leasta portion of the projected target within the environmentally-controlledchamber. With the vehicular camera disposed within the interior of theenvironmentally-controlled chamber, and with the light-collimatingdevice operating to emit collimated light, the method includes capturingimage data with the vehicular camera. The method also includesprocessing, via an image processor, the captured image data and,responsive to processing by the image processor of the captured imagedata, estimating a characteristic of the vehicular camera.

These and other objects, advantages, purposes and features of thepresent invention will become apparent upon review of the followingspecification in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a vehicle with a vision system thatincorporates at least a forward camera module;

FIG. 2 is a perspective view of an environmentally-controlled chamber;

FIG. 3 is a schematic view of a camera under test capturing image datarepresentative of a collimator through a window of a chamber;

FIG. 4 is a perspective view of a collimator mounted at a chamber;

FIG. 5 is a schematic view of a camera capturing image datarepresentative of a target within a collimator; and

FIG. 6 is a perspective view of a camera disposed within a chamber witha collimator mounted external to the chamber.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A vehicle vision system and/or driver assist system and/or objectdetection system and/or alert system operates to capture images exteriorof the vehicle and may process the captured image data to display imagesand to detect objects at or near the vehicle and in the predicted pathof the vehicle, such as to assist a driver of the vehicle in maneuveringthe vehicle in a rearward direction. The vision system includes an imageprocessor or image processing system that is operable to receive imagedata from one or more cameras and provide an output to a display devicefor displaying images representative of the captured image data.Optionally, the vision system may provide display, such as a rearviewdisplay or a top down or bird's eye or surround view display or thelike.

Referring now to the drawings and the illustrative embodiments depictedtherein, a vision system 10 for a vehicle 12 includes at least oneexterior viewing imaging sensor or camera, such as a forward viewingimaging sensor or camera, which may be disposed at and behind thewindshield 14 of the vehicle and viewing forward through the windshieldso as to capture image data representative of the scene occurringforward of the vehicle (FIG. 1 ). Optionally, the system may includemultiple exterior viewing imaging sensors or cameras, such as a forwardviewing camera at the front of the vehicle, and a sideward/rearwardviewing camera at respective sides of the vehicle, and a rearwardviewing camera at the rear of the vehicle, which capture images exteriorof the vehicle. The camera or cameras each include a lens for focusingimages at or onto an imaging array or imaging plane or imager of thecamera. Optionally, the forward viewing camera may be disposed at thewindshield of the vehicle and view through the windshield and forward ofthe vehicle, such as for a machine vision system (such as for trafficsign recognition, headlamp control, pedestrian detection, collisionavoidance, lane marker detection and/or the like). The vision system 10includes a control or electronic control unit (ECU) or processor that isoperable to process image data captured by the camera or cameras and maydetect objects or the like and/or provide displayed images at a displaydevice for viewing by the driver of the vehicle. The data transfer orsignal communication from the camera to the ECU may comprise anysuitable data or communication link, such as a vehicle network bus orthe like of the equipped vehicle.

Cameras have become ubiquitous in automotive and other industries.Traditional environmental testing for automotive cameras measure onlythe camera sharpness before and after the environmental test(s). Testingsharpness and/or defocus of a camera during the environmental test(i.e., when temperature and/or humidity of the camera's environment isvariable) is a challenging task.

Implementations herein include systems and methods for measuring camerasharpness and/or defocus in real time during an environmental test. Thesharpness and defocus are measured using a collimator installed on or ator near an environment-controllable chamber. Optionally, the collimatorincludes submodules such as a light source, a power supply, a target, afocusing lens, and/or a mechanical part (e.g., a lens tube, spacers,etc.). The system or method may include a collimator installed on, at,or near a chamber glass window of the environment-controllable chamber,measurement software, a camera installed within the chamber and having afield of view that includes the chamber window, a tester toretrieve/process the image captured by the camera, and/or configurablechamber parameters such as temperature, humidity and time.

FIG. 2 includes an exemplary environmental chamber 20 that may be usedto house the camera under test. The chamber 20 allows for any number ofenvironmental conditions be controlled (e.g., temperature, humidity,etc.). As shown in FIG. 3 , the chamber 20 includes a window 22 (e.g., aglass or plastic or polycarbonate or other light transmitting materialwindow that allows light to pass into and out of the chamber 20). Thecamera 30 under test is disposed within the chamber 20 (i.e., where thechamber 20 controls one or more environmental parameters of the camera30, such as temperature or humidity) and a collimator 40 is disposedoutside of the chamber 20 (i.e., where the environmentalparameters/conditions are not controlled by the chamber 20). Thecollimator 40 is directed toward the camera 30 and the camera has afield of view that includes at least partially through the window 22.The camera 30 captures image data representative of light that haspassed through the collimator. The collimator 40 may include a target 50(FIG. 5 ) and the image data captured by the camera includes arepresentation of the target. That is, light emitted by the collimator40 passes through the window of the chamber 20 to produce or project avirtual image of the target within the chamber 20 and the camera 30views at least a portion of the virtual image and captures image datarepresentative of the virtual target. Thus, the defocus and sharpness ofthe camera may be tested using the collimator via the target duringenvironmental testing while the camera remains within tightly controlledenvironmental conditions.

FIG. 4 includes an example view of the collimator 40 mounted exterior ofthe chamber 20. The collimator 40 is aligned with the window of thechamber 20 such that light that passes through the collimator 40 entersthe chamber 20 via the window of the chamber 20 (and correspondingly,enters the field of view of the camera 30 within the chamber 20). Thecollimator 40 may be mounted at any position and angle relative to thechamber 20 that allows light that passes through the collimator 40 toenter the chamber 20 via the window. A positionable light source may bepositioned in an area to emit light that will pass through thecollimator 40 with sufficient intensity for the camera 30 to captureimage data representative of the light that passes through thecollimator to illuminate a region viewed by the camera. FIG. 5illustrates the camera 30 capturing an exemplary image that includeslight that has passed through the collimator 40 (and the window) whenthe collimator 40 includes the target 50. The target may be anyappropriate image calibration target, such as a defined shape or grid orpattern. By measuring characteristics of the target 50 in the image(e.g., a size, a position, an orientation, a focus, etc.), the sharpnessand/or defocus on the camera 30 can be estimated and accommodated orcompensated for. For example, based on the characteristics of the target50 (which may be based on or related to characteristics of thecollimator 40, such as a position and/or an angle of the collimator 40relative to the chamber 20 or camera 30), calibration data may beprovided to the camera 30.

The camera 30 may store the calibration data in order to calibrateand/or compensate for any determined deficiencies in sharpness/defocus(or other characteristics) of the camera. The chamber 20 may altervarious environmental conditions/parameters of the camera (e.g.,temperature, humidity, etc.) and, while the conditions are varied, thesharpness/defocus of the camera 30 may be continually or periodicallydetermined. The calibration data may calibrate the camera for specificenvironmental conditions. For example, the calibration data maycompensate for defocus a first amount when the camera is at a firsttemperature while the calibration data may compensate for defocus asecond amount when the camera is at a second temperature. FIG. 6includes an image with a point of view of the interior of the chamber 20with the camera 30 (i.e., an approximate point of view of the camera30). The collimator 40 is visible through the window 22 of the chamber20.

Thus, the camera testing systems and methods herein allow forcharacteristics of a camera 30 to be measured during environmentaltesting. This allows the characteristics of the camera 30 (e.g.,sharpness, defocus, etc.) to be determined at different environmentalconditions/parameters. For example, the system includes a collimatorthat is directed toward a window in an environmentally-controlledchamber. A camera within the chamber captures light that passes throughthe collimator. Based on the image data captured by the camera, variouscharacteristics of the camera may be determined.

The camera or sensor may comprise any suitable camera or sensor.Optionally, the camera may comprise a “smart camera” that includes theimaging sensor array and associated circuitry and image processingcircuitry and electrical connectors and the like as part of a cameramodule, such as by utilizing aspects of the vision systems described inU.S. Pat. Nos. 10,099,614 and/or 10,071,687, which are herebyincorporated herein by reference in their entireties.

The system includes an image processor operable to process image datacaptured by the camera or cameras, such as for detecting objects orother vehicles or pedestrians or the like in the field of view of one ormore of the cameras. For example, the image processor may comprise animage processing chip selected from the EYEQ family of image processingchips available from Mobileye Vision Technologies Ltd. of Jerusalem,Israel, and may include object detection software (such as the typesdescribed in U.S. Pat. Nos. 7,855,755; 7,720,580 and/or 7,038,577, whichare hereby incorporated herein by reference in their entireties), andmay analyze image data to detect vehicles and/or other objects.Responsive to such image processing, and when an object or other vehicleis detected, the system may generate an alert to the driver of thevehicle and/or may generate an overlay at the displayed image tohighlight or enhance display of the detected object or vehicle, in orderto enhance the driver's awareness of the detected object or vehicle orhazardous condition during a driving maneuver of the equipped vehicle.

For example, the vision system and/or processing and/or camera and/orcircuitry may utilize aspects described in U.S. Pat. Nos. 9,233,641;9,146,898; 9,174,574; 9,090,234; 9,077,098; 8,818,042; 8,886,401;9,077,962; 9,068,390; 9,140,789; 9,092,986; 9,205,776; 8,917,169;8,694,224; 7,005,974; 5,760,962; 5,877,897; 5,796,094; 5,949,331;6,222,447; 6,302,545; 6,396,397; 6,498,620; 6,523,964; 6,611,202;6,201,642; 6,690,268; 6,717,610; 6,757,109; 6,802,617; 6,806,452;6,822,563; 6,891,563; 6,946,978; 7,859,565; 5,550,677; 5,670,935;6,636,258; 7,145,519; 7,161,616; 7,230,640; 7,248,283; 7,295,229;7,301,466; 7,592,928; 7,881,496; 7,720,580; 7,038,577; 6,882,287;5,929,786 and/or 5,786,772, and/or U.S. Publication Nos.US-2014-0340510; US-2014-0313339; US-2014-0347486; US-2014-0320658;US-2014-0336876; US-2014-0307095; US-2014-0327774; US-2014-0327772;US-2014-0320636; US-2014-0293057; US-2014-0309884; US-2014-0226012;US-2014-0293042; US-2014-0218535; US-2014-0218535; US-2014-0247354;US-2014-0247355; US-2014-0247352; US-2014-0232869; US-2014-0211009;US-2014-0160276; US-2014-0168437; US-2014-0168415; US-2014-0160291;US-2014-0152825; US-2014-0139676; US-2014-0138140; US-2014-0104426;US-2014-0098229; US-2014-0085472; US-2014-0067206; US-2014-0049646;US-2014-0052340; US-2014-0025240; US-2014-0028852; US-2014-005907;US-2013-0314503; US-2013-0298866; US-2013-0222593; US-2013-0300869;US-2013-0278769; US-2013-0258077; US-2013-0258077; US-2013-0242099;US-2013-0215271; US-2013-0141578 and/or US-2013-0002873, which are allhereby incorporated herein by reference in their entireties. The systemmay communicate with other communication systems via any suitable means,such as by utilizing aspects of the systems described in U.S. Pat. Nos.10,071,687; 9,900,490; 9,126,525 and/or 9,036,026, which are herebyincorporated herein by reference in their entireties.

Changes and modifications in the specifically described embodiments canbe carried out without departing from the principles of the invention,which is intended to be limited only by the scope of the appendedclaims, as interpreted according to the principles of patent lawincluding the doctrine of equivalents.

1. A method for testing a vehicular camera, the method comprising:providing a vehicular camera; providing an environmentally-controlledchamber, wherein the environmentally-controlled chamber comprises awindow allowing visible light to pass from the exterior of theenvironmentally-controlled chamber into the interior of theenvironmentally-controlled chamber; positioning a light-collimatingdevice exterior the environmentally-controlled chamber, wherein, withthe light-collimating device operating to emit collimated light,collimated light emitted by the light-collimating device passes throughthe window of the environmentally-controlled chamber to project a targetwithin the environmentally-controlled chamber; disposing the vehicularcamera within the interior of the environmentally-controlled chamber,wherein, with the light-collimating device operating to emit collimatedlight that passes through the window of the environmentally-controlledchamber to project the target within the environmentally-controlledchamber, the vehicular camera views at least a portion of the projectedtarget within the environmentally-controlled chamber; with the vehicularcamera disposed within the interior of the environmentally-controlledchamber, and with the light-collimating device operating to emitcollimated light, capturing image data with the vehicular camera;processing, via an image processor, the captured image data; andresponsive to processing by the image processor of the captured imagedata, estimating a characteristic of the vehicular camera.
 2. The methodof claim 1, wherein the estimated characteristic of the vehicular cameracomprises at least one selected from the group consisting of (i) imagingsharpness of the vehicular camera and (ii) imaging defocus of thevehicular camera.
 3. The method of claim 1, wherein theenvironmentally-controlled chamber controls at least one selected fromthe group consisting of (i) a temperature of theenvironmentally-controlled chamber and (ii) a humidity of theenvironmentally-controlled chamber.
 4. The method of claim 1, whereinestimating the characteristic of the vehicular camera comprisesdetermining, using the captured image data, a characteristic of theprojected target.
 5. The method of claim 1, further comprisingcapturing, using measurement software, parameters of theenvironmentally-controlled chamber.
 6. The method of claim 5, whereinthe parameters of the environmentally-controlled chamber include atleast one selected from the group consisting of (i) temperature, (ii)humidity and (iii) time.
 7. The method of claim 1, further comprisingdetermining, based on the estimated characteristic of the vehicularcamera, calibration data to compensate for the estimated characteristic,and providing, to the vehicular camera, the calibration data.
 8. Themethod of claim 7, wherein the calibration data is stored at memory ofthe vehicular camera.
 9. The method of claim 1, wherein capturing imagedata with the vehicular camera comprises capturing first image data whenthe environmentally-controlled chamber exposes the vehicular camera to afirst environmental condition and capturing second image data when theenvironmentally-controlled chamber exposes the vehicular camera to asecond environmental condition.
 10. The method of claim 9, whereinestimating the characteristic of the vehicular camera comprisesestimating the characteristic when the vehicular camera is exposed tothe first environmental condition using the first image data andestimating the characteristic when the vehicular camera is exposed tothe second environmental condition using the second image data.
 11. Themethod of claim 1, wherein, with the vehicular camera disposed withinthe interior of the environmentally-controlled chamber, the vehicularcamera at least partially views the light-collimating device through thewindow of the environmentally-controlled chamber.
 12. A method fortesting a vehicular camera, the method comprising: providing a vehicularcamera; providing an environmentally-controlled chamber, wherein theenvironmentally-controlled chamber comprises a window allowing visiblelight to pass from the exterior of the environmentally-controlledchamber into the interior of the environmentally-controlled chamber;positioning a light-collimating device exterior theenvironmentally-controlled chamber, wherein, with the light-collimatingdevice operating to emit collimated light, collimated light emitted bythe light-collimating device passes through the window of theenvironmentally-controlled chamber to project a target within theenvironmentally-controlled chamber; disposing the vehicular camerawithin the interior of the environmentally-controlled chamber, wherein,with the light-collimating device operating to emit collimated lightthat passes through the window of the environmentally-controlled chamberto project the target within the environmentally-controlled chamber, thevehicular camera views at least a portion of the projected target withinthe environmentally-controlled chamber; with the vehicular cameradisposed within the interior of the environmentally-controlled chamber,and with the light-collimating device operating to emit collimatedlight, capturing image data with the vehicular camera; processing, viaan image processor, the captured image data; responsive to processing bythe image processor of the captured image data, determining, using thecaptured image data, a characteristic of the projected target; andresponsive to determining the characteristic of the projected target,estimating a characteristic of the vehicular camera, wherein theestimated characteristic of the vehicular camera comprises at least oneselected from the group consisting of (i) imaging sharpness of thevehicular camera and (ii) imaging defocus of the vehicular camera. 13.The method of claim 12, wherein the environmentally-controlled chambercontrols at least one selected from the group consisting of (i) atemperature of the environmentally-controlled chamber and (ii) ahumidity of the environmentally-controlled chamber.
 14. The method ofclaim 12, further comprising determining, based on the estimatedcharacteristic of the vehicular camera, calibration data to compensatefor the estimated characteristic, and providing, to the vehicularcamera, the calibration data.
 15. The method of claim 14, wherein thecalibration data is stored at memory of the vehicular camera.
 16. Themethod of claim 12, wherein capturing image data with the vehicularcamera comprises capturing first image data when theenvironmentally-controlled chamber exposes the vehicular camera to afirst environmental condition and capturing second image data when theenvironmentally-controlled chamber exposes the vehicular camera to asecond environmental condition.
 17. The method of claim 16, whereinestimating the characteristic of the vehicular camera comprisesestimating the characteristic when the vehicular camera is exposed tothe first environmental condition using the first image data andestimating the characteristic when the vehicular camera is exposed tothe second environmental condition using the second image data.
 18. Amethod for testing a vehicular camera, the method comprising: providinga vehicular camera; providing an environmentally-controlled chamber,wherein the environmentally-controlled chamber comprises a windowallowing visible light to pass from the exterior of theenvironmentally-controlled chamber into the interior of theenvironmentally-controlled chamber; positioning a light-collimatingdevice exterior the environmentally-controlled chamber, wherein, withthe light-collimating device operating to emit collimated light,collimated light emitted by the light-collimating device passes throughthe window of the environmentally-controlled chamber to project a targetwithin the environmentally-controlled chamber; disposing the vehicularcamera within the interior of the environmentally-controlled chamber,wherein, with the light-collimating device operating to emit collimatedlight that passes through the window of the environmentally-controlledchamber to project the target within the environmentally-controlledchamber, the vehicular camera views at least a portion of the projectedtarget within the environmentally-controlled chamber; with the vehicularcamera disposed within the interior of the environmentally-controlledchamber during a first environmental condition of theenvironmentally-controlled chamber, and with the light-collimatingdevice operating to emit collimated light, capturing first image datawith the vehicular camera; processing, via an image processor, thecaptured first image data; responsive to processing by the imageprocessor of the captured first image data, estimating a characteristicof the vehicular camera when the vehicular camera is exposed to thefirst environmental condition; after capturing the first image data withthe vehicular camera, changing the first environmental condition of theinterior of the environmentally-controlled chamber to a secondenvironmental condition; with the vehicular camera disposed within theinterior of the environmentally-controlled chamber during the secondenvironmental condition of the environmentally-controlled chamber, andwith the light-collimating device operating to emit collimated light,capturing second image data with the vehicular camera; processing, viathe image processor, the captured second image data; responsive toprocessing by the image processor of the captured second image data,estimating the characteristic of the vehicular camera when the vehicularcamera is exposed to the second environmental condition; anddetermining, based on the estimated characteristic of the vehicularcamera when exposed to the first environmental condition and theestimated characteristic of the vehicular camera when exposed to thesecond environmental condition, calibration data to compensate for theestimated characteristic at the first environmental condition and tocompensate for the estimated characteristic at the second environmentalcondition.
 19. The method of claim 18, further comprising capturing,using measurement software, parameters of the environmentally-controlledchamber.
 20. The method of claim 19, wherein the parameters of theenvironmentally-controlled chamber include at least one selected fromthe group consisting of (i) temperature, (ii) humidity and (iii) time.21. The method of claim 18, wherein the estimated characteristic of thevehicular camera comprises at least one selected from the groupconsisting of (i) imaging sharpness of the vehicular camera and (ii)imaging defocus of the vehicular camera.